Novel Photothermal Regulation Technologies for Energy-saving: Active Electrochromism and Passive Radiative Cooling

The development of novel energy-efficient cooling technologies is of significant importance for the realization of effective building thermal management and energy-saving. Radiation is the most ubiquitous mode of heat transfer in nature,where solar and environmental thermal radiation plays a vital role serving as two critical energy vectors. The photothermal regulation could modulate the solar and thermal radiation properties, thus managing the internal temperature of objects. Materials exhibit varied spectral responses to solar and thermal radiations according to the specific demands of different scenarios,which could be categorized into active and passive photothermal control materials. Active photothermal regulation materials are favored for their high tunability and low energy consumption,while passive photothermal regulation materials are recognized for their zero-energy consumption and robust temperature regulation capabilities,both garnering extensive attention from researchers. This article, exemplifying active control and passive control with electrochromic materials and radiative cooling,respectively,focuses on outlining the regulatory principles of these emerging photothermal control technologies. It reviews the development of electrochromic and radiative cooling materials based on spectral design strategies and principles,and further summarizes the existing challenges and future development directions,providing a comprehensive perspective for researchers in the field of building energy saving. © 2025 Cailiao Daobaoshe/ Materials Review. All rights reserved.